A primary advance in personal oral health care has been the manual toothbrush, which allows the individual to take daily care of their oral hygiene. However, user compliance with twice-daily brushing is a perennial problem, with the average user spending little more than 40 seconds cleaning their teeth, with demonstrable poor oral health, simply because the user does not brush long enough to remove the plaque that can be reached by the bristles. Power brushes, used by 25% of people in the United States, have offered the potential for a significant advance in self-care, because those brushes (1) can efficiently remove plaque they can reach relative to manual brushes and (2) can remove some of the 50% of total plaque in the mouth that is beyond the reach of their bristles, plaque that is unreachable by manual brushes. Problems remain, however. Many of these power toothbrushes require two minutes of brushing to achieve these effects - a complaint of many users that results in reduced user compliance. And, a significant amount of plaque still remains after brushing with even the leading power toothbrushes. Therefore, the development of a power brush capable of removing the majority plaque both within reach of and beyond the reach of the bristles over a period of time sufficiently short (e.g., 1 minute) to meaningfully enhance patient compliance would mark a significant advance in oral health. Preliminary results obtained in vitro support the possibility of creating such a toothbrush. It has been shown that sonically induced, macroscopic fluid motion in the form of a bubbly jet generated by a mechanically altered toothbrush can rapidly and effectively remove plaque beyond the reach of the bristles. Additionally, bubbles stimulated with low levels of ultrasound can also rapidly remove plaque beyond the reach of the bristles, as can the combination of these physical processes. The purpose of this proposal is to study the effect of novel sonic and ultrasound-based physical processes on plaque while demonstrating the potential utility and feasibility of a power toothbrush with these processes.